02 lan devices

8/8/2019 02 LAN Devices

1/22

Chapter 2LAN Devices


2/22

INTERNETWORK

ING DEV

ICES

Repeaters

BridgesRouters / Gateways

ConcentratorsHubsEther Switches


3/22

REPEATER

T o interconnect segments

T o overcome segment lengthlimitations / Restrictions

T o Amplify / Regenerate Signal


4/22

REPEA T ER

Active Device used to extend the segment length

Amplification & Regeneration of signal so thatsignal can be transmitted over long distancesForms single collision & broadcast domain


5/22

T TT10 Base5

Upto 100 taps

10 Base5Upto 100 taps

T

REPEA T ER


6/22

Hub

Device that serves as the center of Device that serves as the center of

a star topology network, sometimesa star topology network, sometimesreferred to as areferred to as a multiport repeater multiport repeater ,,or in Ethernet, aor in Ethernet, a concentrator concentrator ;; nonoforwarding intelligenceforwarding intelligence


7/22

HUB SCommon wiring point for star topology networksCommon synonym for Concentrator

Active and Passive Hubs in ArcnetT wisted Pair Hubs in 10 Base TM anageable / Non manageableIntelligent / M odular HubsStackable / Cascade


8/22


9/22

Bridge

Device that connects and passesDevice that connects and passespackets between two networkpackets between two network

segments.segments.More intelligent than hubMore intelligent than hub analyzesanalyzesincoming packets and forwards (or incoming packets and forwards (or filters) them based on addressingfilters) them based on addressinginformation.information.


10/22

B R IDGE

Filters T rafficImproves Overall T hroput

Data link layer deviceT ransparent unaffected by diff in protocolNo configuration required, learnsNW by itself


11/22

B ridge

Segment 1 Segment 2

H ub H ub

M ore intelligent than a hubcan analyze incoming packets and forward(or filter) them based on addressing informationCollects and passes packets between two network segmentsM aintains address tablesDifferent types of bridges: transparent and source route (used primarily inT oken Ring LANs)

Bridge Example


12/22

Switches

UseUse bridging technologybridging technology totoforward traffic between ports.forward traffic between ports.

Provide fullProvide full dedicateddedicated datadatatransmission rate between two stationstransmission rate between two stationsthat are directly connected to the switchthat are directly connected to the switchports.ports.

Build and maintainBuild and maintain addressaddresstablestables called contentcalled content- -addressableaddressablememory (CA M ).memory (CA M ).


13/22

10-MbpsU TP Cable

Dedicated

Workstation

Switch

100 Mbps

Uses bridging technology to forward traffic (i.e.maintains address tables, and can filter)Provides full dedicated transmission rate betweenstations that are connected to switch portsUsed in both local-area and in wide-area networking

All types availableEthernet, T oken Ring, A TM

SwitchingDedicated M edia


14/22

SWI T CHING T ECHNOLOGY

Like bridges, only faster Segments LAN into smaller collision domains

Protocol transparentSimplifies adds, moves and changesHigh aggregate bandwidthPerformance delivered over more ports for a

lower cost/port


15/22

SWI T CHING T ECHNOLOGYCON T D.

Operates at Layer 2 of the OSI modelLearns location of devices based on source M AC

addressForwarding based on destination M AC address

Special-purpose deviceLAN segmentation to provide additional bandwidth

Expected to forward large amounts of trafficHigh throughput with low latency


16/22

Routers

Interconnect LANs and WANsInterconnect LANs and WANsProvide path determination usingProvide path determination usingmetricsmetricsForward packets from oneForward packets from onenetwork to another network to another Control broadcasts to the networkControl broadcasts to the network

Interconnect LANs and WANsInterconnect LANs and WANsProvide path determination usingProvide path determination usingmetricsmetricsForward packets from oneForward packets from onenetwork to another network to another Control broadcasts to the networkControl broadcasts to the network


17/22

Routing T echnology

Operates at Layer 3 of the OSI modelRequired to distinguish among different

network layer protocolsProtocol knowledge allows more intelligent

forwarding decisionsDesigned to flexibly address a number of different applications

Limit broadcast trafficFirewall security


18/22

Routing T echnology contd.

Redundant active pathsWAN access

T wo basic functionsM aintain a routing table for each network layer protocolForward each frame based on network layer

address


19/22

MODE

M

M ODULA T IONChanging of one or more of the parametersof a waveform (sine) (carrier) as per themessageM ODE Mwhich interfaces digital data into a format which makes it possible to transmit over unconditioned telephone linesInput can be sync or async output can be 2 wire or 4 wire


20/22

MODE

MFEA

TURES

LEASED LINE / DIAL UP2 WIRE / 4 WIRESPEED OF A M ODE M

ORIGINA T E/ANSWER

ST ANDALONE PC CONNEC

TED


21/22

COM

PONENT

S OFM

ODEM

POWER SUPPLY (S T AND ALONE)M ICROPROCESSOR AND M EM ORYRS 232 IN T ERFACET ELEPHONE LINE DRIVERM

ODEM


22/22

End of Chapter 2

Questions

02 lan devices

Documents